Description

IPR012164 is a DNA-directed RNA polymerase subunit/transcription factor S.

<p>DNA-directed RNA polymerases [ec:2.7.7.6] (also known as DNA-dependent RNA polymerases) are responsible for the polymerisation of ribonucleotides into a sequence complementary to the template DNA. In eukaryotes, there are three different forms of DNA-directed RNA polymerases transcribing different sets of genes. Most RNA polymerases are multimeric enzymes and are composed of a variable number of subunits. The core RNA polymerase complex consists of five subunits (two alpha, one beta, one beta-prime and one omega) and is sufficient for transcription elongation and termination but is unable to initiate transcription. Transcription initiation from promoter elements requires a sixth, dissociable subunit called a sigma factor, which reversibly associates with the core RNA polymerase complex to form a holoenzyme [[cite:PUB00000061]]. The core RNA polymerase complex forms a "crab claw"-like structure with an internal channel running along the full length [[cite:PUB00033173]]. The key functional sites of the enzyme, as defined by mutational and cross-linking analysis, are located on the inner wall of this channel.</p> <p>RNA synthesis follows after the attachment of RNA polymerase to a specific site, the promoter, on the template DNA strand. The RNA synthesis process continues until a termination sequence is reached. The RNA product, which is synthesised in the 5' to 3' direction, is known as the primary transcript.</p> <p>Eukaryotic nuclei contain three distinct types of RNA polymerases that differ in the RNA they synthesise:</p> <ul> <li>RNA polymerase I: located in the nucleoli, synthesises precursors of most ribosomal RNAs.</li> <li>RNA polymerase II: occurs in the nucleoplasm, synthesises mRNA precursors.</li> <li>RNA polymerase III: also occurs in the nucleoplasm, synthesises the precursors of 5S ribosomal RNA, the tRNAs, and a variety of other small nuclear and cytosolic RNAs.</li> </ul> <p>Eukaryotic cells are also known to contain separate mitochondrial and chloroplast RNA polymerases. Eukaryotic RNA polymerases, whose molecular masses vary in size from 500 to 700kDa, contain two non-identical large (>100kDa) subunits and an array of up to 12 different small (less than 50kDa) subunits.</p> <p>In archaebacteria, there is generally a single form of RNA polymerase which also consist of an oligomeric assemblage of 10 to 13 polypeptides.</p> <p>This entry represents the conserved small (~15kDa), zinc ribbon-containing, subunit which is found in archaeal and eukaryotic polymerases and forms part of the catalytic core of the enzyme [[cite:PUB00008731], [cite:PUB00029086], [cite:PUB00018563]]. This entry also includes transcription factor S (TFS), a protein related in size and sequence to DNA-directed RNA polymerase subunit M, and in sequence and function to the much larger eukaryotic transcription factor IIS (TFIIS). Although originally suggested to be a subunit of the archaeal RNA polymerase (known as archaeal DNA-directed RNA polymerase subunit M), it elutes separately from active polymerase in gel filtration experiments and acts, like TFIIs, as an induction factor for RNA cleavage by RNA polymerase [[cite:PUB00009536], [cite:PUB00078615], [cite:PUB00099581]].</p>

This description is obtained from EB-eye REST.

Associated GO terms

GO predictions are based solely on the InterPro-to-GO mappings published by EMBL-EBI, which are in turn based on the mapping of predicted domains to the InterPro dataset. The InterPro-to-GO mapping was last updated on April 27, 2020, while the GO metadata was last updated on April 27, 2020.

Associated Lotus transcripts 7

Co-occuring domains 1

A list of co-occurring predicted domains within the L. japonicus gene space: